Location of the Cannula of the Left Ventricular Assist Device in Explanted Hearts After Orthotopic Heart Transplantation

Abstract

Many patients having orthotopic heart transplantation (OHT) have previously had a left ventricular assist device (LVAD). Such a scenario allows the study of the position of the LVAD cannula in the explanted heart. We studied the explanted hearts in 105 patients who had had a LVAD inserted earlier and later underwent OHT at Baylor University Medical Center from January 2005 to September 2019, and compared the patients in whom the margins of the LVAD cannula contacted the mural endocardium with those in whom it did not. The margins of the orifice of the LVAD cannula contacted the left ventricular (LV) mural endocardium in 38 (36%) patients (considered potentially hazardous insertion) whereas in 67 (64%) patients there was no contact (considered "ideal" insertion). Comparison of the patients with ideal cannular insertion to those with potentially hazardous insertion disclosed insignificant differences in age at LVAD insertion or OHT; gender; interval between the LVAD insertion and OHT; body mass index; underlying cardiac disease; whether or not the heart floated in a container of formaldehyde, and the type of LVAD inserted. The margins of the LVAD cannula contacted the LV mural endocardium significantly more in patients with smaller mean heart weights than those with larger mean heart weights. In conclusion, of the 105 patients studied, the cannula of the LVAD resided in the LV cavity at an angle that allowed the margins of the orifice of the cannula to contact the mural endocardium in 38 (36%), a situation that at least potentially could cause partial obstruction of its orifice. Nevertheless, comparison of the 38 patients with nonideal cannular insertion to the 67 with ideal cannular insertion disclosed only 1 significant difference between the 2 groups.